1. Field of Invention
This invention relates to an internal fluid tank venting structure in a refillable fluid container.
2. Description of Related Art
Fluid ejector systems, such as drop-on-demand liquid ink printers, have at least one fluid ejector from which droplets of fluid are ejected towards a receiving sheet. Scanning inkjet printers are equipped with fluid ejection heads containing fluid ink. The ink is applied to a sheet in an arrangement based on print data received from a computer, scanner or similar device. To control the delivery of the fluid to the sheet, fluid ejection heads are moved across the sheet to provide the fluid to the sheet, which is ejected as drops. These drops correspond to a liquid volume designated as pixels. Each pixel is related to a quantity needed to darken or cover a particular unit area.
Integral fluid filters are known. Examples of such integral fluid filters, used for ink jet printheads, are U.S. Pat. No. 4,639,748 to Drake et al., U.S. Pat. No. 5,124,717 to Campanelli et al., U.S. Pat. No. 5,141,596 to Hawkins et al., and U.S. Pat. No. 5,204,690 to Lorenze, Jr. et al.
Of these, only U.S. Pat. No. 4,639,748 includes an integral, internal ink filter positioned within the channel plate before the individual ink channel nozzles. The other cited references include a membrane filter fabricated over an ink fill opening between an ink supply cartridge and the ink manifold of the printhead (i.e., external to the channel plate and affixed to an outer face thereof). As such, these latter patents require additional fabrication costs and time to pattern and implement the ink filter assembly. Further, such a filter is quite removed from the nozzles.